This invention relates to systems and methods for automatically controlling and optimizing a combustion process to maintain high combustion efficiency while also minimizing pollutants and other harmful by-products. More specifically, this invention uses an expert system fuzzy logic controller and a neural network to analyze various forms of data gathered from image and other sensors, and to optimize the combustion process by automatically varying combustion control parameters.
Combustion plants, furnaces and engines of various forms are well known. They are used to heat homes, cook food, power factories, and to propel many different types of vehicles. Combustion systems evolved through the centuries from simple open fires to modern centralized boilers and hot air furnaces. Combustion machines used to power vehicles include steam engines, piston engines, turbines, jet engines and rockets. Large-scale combustion plants generate electrical power to provide power for communities and cities.
The combustion process, itself, is also well known. In general, most combustion systems operate by burning a wide variety of hydrocarbon fuels, including natural gas, oil, coal and refuse. As such, the combustion process is an exothermic, or heat producing, chemical reaction between a fuel and oxygen. A high temperature is used to ignite the reaction, which causes burning of the air and fuel reactants. The burning process converts the hydrocarbon fuel and oxygen to carbon dioxide, water and other combustion byproducts. The combustion process breaks the molecular bond structure of the reactants, and yields combustion products that are at a lower thermodynamic potential energy than the original reactants. The change in potential energy level generates kinetic energy in the form of heat, which is used as a source of power. For additional background information regarding the combustion process, see the following publications, each of which is incorporated herein by reference: Strahle, Warren C., An Introduction to Combustion, Gordon and Breach Science Publishers, S.A., Longhorne, Pa. (1993), ISBN 2-88124-586-2; Strehlow, Roger A., Combustion Fundamentals, McGraw-Hill, New York (1984), ISBN 0-07-062221-3; Barnard, J. A., Flame and Combustion, Chapman and Hall, New York (1985), ISBN 0-412-23030-5.
There has been much innovation in the development of modern combustion plants and engines. However, the proliferation and size of all kinds of combustion plants is a source of increasing environmental concern. For example, environmental problems traced to combustion power plants are now better understood, including specifically relating to effects such as smog, acid rain, global warming and depleting combustible natural resources. As a result, attention has been directed at improving the combustion process with the goals of increasing efficiency and minimizing negative side effects and byproducts. Examples of such attempts are found in the following U.S. Patents: (a) U.S. Pat. No. 5,479,358; (b) U.S. Pat. No. 5,473,162; (c) U.S. Pat. No. 5,471,937; (d) U.S. Pat. No. 5,430,642; (e) U.S. Pat. No. 5,361,628; (f) U.S. Pat. No. 5,311,421; (g) U.S. Pat. No. 5,305,230; (h) U.S. Pat. No. 5,303,684; (i) U.S. Pat. No. 5,285,959; (j) U.S. Pat. No. 5,257,496; (k) U.S. Pat. No. 5,249,954; (l) U.S. Pat. No. 5,247,445; (m) U.S. Pat. No. 5,227,975; (n) U.S. Pat. No. 5,213,077; (o) U.S. Pat. No. 5,205,486; (p) U.S. Pat. No. 5,178,002; (q) U.S. Pat. No. 5,158,024; (r) U.S. Pat. No. 5,146,898; (s) U.S. Pat. No. 5,129,379; (t) U.S. Pat. No. 5,065,728; (u) U.S. Pat. No. 5,050,083; (v) U.S. Pat. No. 4,966,118; (w) U.S. Pat. No. 4,926,826; (x) U.S. Pat. No. 4,889,099; and (y) U.S. Pat. No. 4,881,505. See also the following publications: (a) Progress in Emission Control Technologies, Society of Automotive Engineers (1994), ISBN 1-56091-565-X; (b) Advanced Emission Control Technologies, Society of Automotive Engineers (1993), ISBN 1-56091-436-X; (c) Hanby, V.I., Combustion and Pollution Control in Heating Systems, Springer Verlag, N.Y. (1993), ISBN 3-540-19849-0; (d) Eckbreth, Alan C., Laser Diagnostics for Combustion Temperature and Species, Abacus Press, Cambridge Mass. (1988), ISBN 0-85626-344-3; and (e) Crosley, David R., Laser Probes for Combustion Chemistry, American Chemical Society Symposium Series, American Chemical Society, Washington, D.C. (1980), ISBN 0-8412-0570-1. Each of the above-listed patents and publications is incorporated herein by reference.
While the above-listed patents and publications disclose various attempts to characterize and control the combustion process, none of them take full advantage of modern imaging and control technology. For example, none of the systems combine modern computer imaging techniques with expert systems using fuzzy logic and neural networks to optimize the combustion process through automatic feedback control of the combustion parameters. The need exists for improved Systems and methods that automatically optimize the combustion process to increase efficiency and minimize unwanted or harmful by-products. In view of the wide spread use of combustion systems that burn hydrocarbon fuels, even small improvements in the efficiency of the combustion process can result in significant social and environmental benefits.
It is an object of the invention to provide automatic combustion optimization systems and methods that improve combustion efficiency and lower pollutant emissions.
It is another object of the invention to provide improved combustion control systems and methods that combine image analysis and sensing of other combustion parameters to automatically optimize the combustion process using expert systems implemented with fuzzy logic and neural networks.
It is another object of the invention to automatically generate combustion control signals by analyzing video signals resulting from scanning the combustion process.
It is another object of the invention to provide automatic combustion control systems and methods that generate signals for analysis by using laser scanners to scan a combustion chamber and combustion exhaust gases.
It is another object of the invention to provide automatic combustion control systems and methods that analyze video scanning signals to evaluate the concentration of reactants and the quality of the combustion flame, and that generate feedback control signals based on such as an evaluation.
It is a another object of the invention is to automatically analyze combustion temperature and video and laser scanning signals to control and optimize the combustion process.
It is another object of this invention is to provide automatic combustion optimization systems and methods using neural networks to analyze image signals and classify characteristics of the combustion process, such as flame grade.
It is another object of the invention to provide automatic combustion optimization systems and methods using a fuzzy logic controller to analyze a variety of sensor outputs, including flame grade classification determined from image analysis.
It is another object of the invention to provide a fuzzy logic rule base useful for analyzing a variety of parameters to optimize the combustion process.
It is another object of the invention to provide a fuzzy logic rule base and associated expert system that analyze and respond to changes in a variety of combustion parameters to control and optimize the combustion process.
It is another object of the invention to provide automatic combustion optimization systems and methods that compensate for inaccuracies and uncertainties in image signals and other sensor outputs that are used to measure volatile combustion processes.
It is another object of the invention to provide systems and methods that automatically monitor and control the combustion process for optimal operation in a xe2x80x9cleanxe2x80x9d burn region.
It is another object of the invention to provide systems and methods that automatically monitor and control both the fuel and air flow rates into a combustion chamber.
It is another object of the invention to provide automatic combustion optimization systems and methods that adjust the air to fuel ratio to maintain combustion parameters within a xe2x80x9cwindowxe2x80x9d or region about specified set points.
It is another object of the invention to provide automatic combustion optimization systems and methods that use a fuzzy logic controller to minimize the emissions of nitric oxides and/or other pollutants while still maintaining an efficient and adequate rate of combustion.
It is another object of the invention to provide systems and methods that automatically monitor and control the rate of turbulence in the inlet and combustion chamber to improve the overall combustion process.
Further objects of the invention are apparent from reviewing the Summary of the Invention, Detailed Description and appended claims, which are each set forth below.
The above and other objects are achieved in the present inventions, which provide automatic combustion control systems and methods implementing neural networks to analyze video data resulting from scanning or imaging various aspects of the combustion process. Additional sensors monitor and generate input signals that define other parameters of the combustion process, such as fuel flow, air flow, air to fuel ratio, inlet turbulence and combustion turbulence. An expert computer system uses a fuzzy logic rule base to analyze the various data inputs and to determine if any adjustments are necessary to optimize the combustion process. The expert system automatically generates feedback control signals to vary the combustion parameters to maintain optimal combustion efficiency while minimizing fuel use and the generation of harmful byproducts.
The control systems and methods of the present inventions optimize the combustion process in a furnace, incinerator, internal combustion engine or reactor. Computer image analysis or machine vision techniques implementing neural networks analyze video data resulting from scanning parameters of the combustion process, such as flame and fireball structure. Detected variations in the combustion parameters, such as the shapes, sizes and propagation of flame and fireball, are analyzed to determine and characterize combustion efficiencies. Adjustments to the combustion parameters are automatically implemented to optimize burning and reduce or eliminate pollution.
The preferred embodiments of the inventions are described below in the Figures and Detailed Description. Unless specifically noted, it is applicant""s intention that the words and phrases in the specification and claims be given the ordinary and accustomed meaning to those of ordinary skill in the applicable art(s). If applicant intends any other meaning, he will specifically state that he is applying a special meaning to a word or phrase.
Likewise, applicant""s use of the word xe2x80x9cfunctionxe2x80x9d in the Detailed Description is not intended to indicate that he seeks to invoke the special provisions of 35 U.S.C. Section 112, ¶ 6 to define his invention. To the contrary, if applicant wishes to invoke the provisions of 35 U.S.C. Section 112, ¶ 6 to define his invention, he will specifically set forth in the claims the phrases xe2x80x9cmeans forxe2x80x9d or xe2x80x9cstep forxe2x80x9d and a function, without also reciting in that phrase any structure, material or act in support of the function. Moreover, even if applicant invokes the provisions of 35 U.S.C. Section 112, ¶ 6 to define his invention, it is applicant""s intention that his inventions not be limited to the specific structure, material or acts that are described in his preferred embodiments. Rather, if applicant claims his invention by specifically invoking the provisions of 35 U.S.C. Section 112, ¶ 6, it is nonetheless his intention to cover and include any and all structures, materials or acts that perform the claimed function, along with any and all known or later developed equivalent structures, materials or acts for performing the claimed function.
For example, the present inventions generate image information for analysis by scanning the combustion process using any applicable image or video scanning system or method. The inventions described herein are not to be limited to the specific scanning or imaging devices disclosed in the preferred embodiments, but rather, are intended to be used with any and all applicable electronic scanning devices, as long as the device can generate an input signal that can be analyzed by a computer to detect variations in the combustion process or characteristics. Thus, the scanners or image acquisition devices are shown and referenced generally throughout this disclosure, and unless specifically noted, are intended to represent any and all devices appropriate to scan or image the combustion process.
Likewise, it is anticipated that the physical location of the scanning device is not critical to the invention, as long as it can scan or image the combustion flame. Thus, the scanning device can be configured to scan the combustion process either directly or through a high temperature resistant window or transparent wall of the combustion chamber. Alternatively, the scanning device may scan or image the combustion process using a light pipe, such as a fiber-optic bundle extending to or through an opening in the combustion chamber wall and terminating within or adjacent the combustion region. Accordingly, the words xe2x80x9cscanxe2x80x9d or xe2x80x9cimagexe2x80x9d as used in this specification should be interpreted broadly and generically.
Further, there are disclosed several computers or controllers, that perform various control operations. The specific form of computer is not important to the invention. In its preferred form, applicant divides the computing and analysis operations into several cooperating computers or microprocessors. However, with appropriate programming well known to those of ordinary skill in the art, the inventions can be implemented using a single, high power computer. Thus, it is not applicant""s intention to limit his invention to any particular form of computer.
Further examples exist throughout the disclosure, and it is not applicant""s intention to exclude from the scope of his invention the use of structures, materials or acts that are not expressly identified in the specification, but nonetheless are capable of performing a claimed function.